---
title: Claude Opus 4.7 Breaks temperature and top_p Params
description: Claude Opus 4.7 returns HTTP 400 for temperature, top_p, top_k, and budget_tokens in some configurations. What changed and how to fix it.
date: 2026-08-12T00:00:00.000Z
category: ai-productivity
tags: claude, anthropic, api
---

## Quick Answer

Third-party technical coverage reports that Claude Opus 4.7 introduced a breaking change: passing `temperature`, `top_p`, `top_k`, or `budget_tokens` together in some configurations now returns an HTTP 400 error instead of a response. Anthropic's own GA changelog doesn't confirm this. If a previously-working call suddenly errors after upgrading, check these parameters first.

## What's actually changing

Third-party technical coverage of Opus 4.7, the same source cluster reporting the tokenizer change covered separately in this series, reports that certain sampling parameters now trigger HTTP 400 errors under some configurations: `temperature`, `top_p`, `top_k`, and `budget_tokens`, a restriction independently confirmed for `temperature`, `top_p`, and `top_k` in [Anthropic's own API release notes](https://docs.claude.com/en/release-notes/api). Previously valid combinations of these parameters are reported to fail outright rather than degrade gracefully or get silently ignored.

As with the tokenizer claim, this is explicitly not confirmed by Anthropic's own official GA changelog for Opus 4.7 (2026-04-16), which does not mention this behavior. Treat the exact trigger conditions as reported, not verified, and confirm against your own test calls before assuming a specific parameter combination is the cause.

## Structural Comparison Matrix

| Operational Aspect                             | Opus 4.6 and earlier | Opus 4.7+                                          |
| :--------------------------------------------- | :------------------- | :------------------------------------------------- |
| **`temperature` / `top_p` / `top_k` together** | Accepted             | Reported to return HTTP 400 in some configurations |
| **`budget_tokens`**                            | Accepted             | Reported to return HTTP 400 in some configurations |
| **Anthropic's own GA changelog**               | N/A                  | Does not mention this behavior                     |

## Fix it: isolate the failing parameter combination

If a request that worked before an Opus 4.7 upgrade now returns HTTP 400, the fastest path is elimination, not guessing. Strip `temperature`, `top_p`, `top_k`, and `budget_tokens` down to the minimum your call actually needs, then add them back one at a time against a real test request until the error reappears. That isolates the specific combination your integration is hitting, since the reported behavior is not confirmed to be identical across every configuration.

Once identified, the fix is usually straightforward: drop the redundant parameter rather than fight the error. Sending both `temperature` and `top_p` on the same request was already redundant in most sampling setups, since both control the same underlying randomness in different ways; picking one instead of both often resolves the error without changing the model's actual output behavior much.

If you're also re-checking cost impact while you're in here, the [LLM Pricing Calculator](/tools/llm-pricing-calculator/) covers Claude Opus 4.7's current pricing and caching math separately from this parameter issue.

## Confirmed version

Sourced from the same third-party technical coverage of Opus 4.7 that reports the tokenizer change, not Anthropic's own materials directly. GA date 2026-04-16 confirmed via GitHub's official changelog, which does not itself confirm this specific claim. Browse more coverage in the [AI Productivity](/ai-productivity) archive, or start from [The 2026 LLM Token & Pricing Reset](/ai-productivity/2026-llm-token-pricing-reset/) hub.